Quantum key distribution-based OTN encryption communication method and system

Abstract

Disclosed in the present invention are a quantum key distribution-based OTN encryption communication method and a system. The method comprises: applying to a quantum key distribution network for a session key, and establishing the association between the session key and a corresponding encryption policy; dividing the frame structure of any layer in an optical channel layer into an overhead area and a payload area; when a current sender OTN device supports adding information in the overhead area, adding in the overhead area a session key sequence number used for encrypting the present frame of a current port, using the session key to encrypt the payload area of the current frame on the basis of the encryption policy, and then sending the entire frame to a peer end OTN device; and when the current sender OTN device does not support adding information in the overhead area, using the session key to encrypt the payload area of the current frame on the basis of the encryption policy, then sending the frame to the peer end OTN device, and periodically sending a session key synchronization packet to the peer end OTN device. The present invention improves the reliability by using two key synchronization modes, i.e., a mode of supporting adding information in a frame and a mode of notifying by means of a management channel.

Description

OTN encryption communication method and system based on quantum key distribution Technical Field

[0001] The present invention relates to the technical field of quantum secure communication, and in particular to an OTN encryption communication method and system based on quantum key distribution. Background Art

[0002] With the development of optical communication technology, the deployment and use of optical transport networks (OTNs) are becoming increasingly widespread. OTN is a type of network that implements the transmission, multiplexing, routing, and monitoring of service signals within the optical domain, while ensuring their performance and survivability. OTN technology is a compromise between electrical networks and all-optical networks. It transplants the powerful and comprehensive OAM&P concepts and functions of the Synchronous Digital Hierarchy (SDH) to wavelength division multiplexing (WDM) optical networks, effectively addressing the shortcomings of existing WDM systems in performance monitoring and maintenance management. OAM&P refers to the division of network management tasks into three categories based on the actual needs of the operator's network operations: operation, administration, and maintenance. OAM stands for provisioning, and the goal is to achieve intelligent network management.

[0003] OTN technology supports transparent transmission of customer signals, high-bandwidth multiplexing, switching, and configuration (the minimum cross-connect granularity is ODU1, approximately 2.5 Gbit / s). It offers robust overhead support, powerful Operational and Administering (OAM) capabilities, multi-layer nested Tandem Connection Monitor (TCM), and forward error correction (FEC). The OTN frame structure of the optical channel layer significantly enhances the digital monitoring capabilities of the optical channel layer (OCh), enabling both end-to-end and multi-segment performance monitoring in OTN networks.

[0004] Compared to SDH and WDM networks, which use IPSec to address end-to-end security, OTN offers a wider range of technical solutions for key synchronization, online key distribution, and encrypted payload framing, making it easier to implement end-to-end direct encryption across OTN nodes. The emergence and continued maturity of quantum key distribution (QKD) technology is providing strong support for end-to-end direct encryption within OTN. OTN and QKD co-fiber technology enable the transmission of keys and encrypted data over the same physical channel.

[0005] In related technologies, patent application document CN108667526A proposes using QKD to provide quantum keys in combination with the Advanced Encryption Standard (AES) algorithm to add an optical channel encryption unit (OEUk) between the optical channel data unit (ODUk) and the optical channel transport unit (OTUk) of the OTN to perform unified encryption and decryption of the ODUk-borne services, thereby achieving secure transmission of multiple services. This solution modifies the OTN structure and adds an OEUk layer, but does not address the issue of key synchronization.

[0006] The patent application document with publication number CN111224772A proposes that upon receiving a first key application request from an encryption end and a second key application request from a decryption end and verifying both, a key management end sends a first key to the encryption end and a decryption end, respectively. This enables the encryption end and the decryption end to simultaneously apply for the same key from the key management end, thereby improving the convenience of key distribution and management in the OTN transmission system.

[0007] Summary of the Invention

[0008] The technical problem to be solved by the present invention is how to achieve end-to-end direct encrypted communication between OTN device nodes in different security domains and improve communication reliability.

[0009] The present invention solves the above technical problems through the following technical means:

[0010] In a first aspect, the present invention proposes an OTN encryption communication method based on quantum key distribution, which is applied to a sender OTN device. The method includes:

[0011] Apply for a session key from a quantum key distribution network and associate the session key with a corresponding encryption policy;

[0012] Divide the frame structure of any layer in the optical path layer into an overhead area and a payload area;

[0013] When the current sending OTN device supports adding information to the overhead area, the session key sequence number used for encrypting the current frame on the current port is added to the overhead area, and the payload area of ​​the current frame is encrypted using the session key based on the encryption policy before the entire frame is sent to the peer OTN device.

[0014] When the current sending OTN device does not support additional information in the overhead area, the payload area of ​​the current frame is encrypted using the session key based on the encryption strategy and then sent to the opposite OTN device, and a session key synchronization message is periodically sent to the opposite OTN device.

[0015] In a second aspect, the present invention proposes an OTN decryption communication method based on quantum key distribution, which is applied to a receiving OTN device. The method includes:

[0016] Receive the session key issued by the quantum key distribution network and associate the session key with the corresponding encryption policy; when the current receiving OTN device supports adding information in the overhead area, obtain the session key sequence number used for encrypting the current frame of the current port inbound traffic from the overhead area;

[0017] When the current receiving OTN device does not support adding information in the overhead area, the session key sequence number used for encrypting the port's inbound traffic is obtained from the key synchronization message sent by the opposite OTN device.

[0018] A session key associated with the encryption policy is obtained based on the session key sequence number, and the ciphertext information sent by the opposite-end OTN device is decrypted.

[0019] In a third aspect, the present invention proposes a session key distribution method, which is applied to a key controller. The method comprises: receiving a key application message sent by a local OTN device;

[0020] After verifying that the key application message is passed, query the cryptographic service platform for the QKD node information of the opposite OTN device; obtain the session key and key start and end sequence numbers from the key pool corresponding to the QKD link between the QKD node of the local OTN device and the QKD node of the opposite OTN device, and report the key start and end sequence numbers to the cryptographic service platform so that the cryptographic service platform sends the key start and end sequence numbers and the QKD node information of the local OTN device to the key controller corresponding to the opposite OTN device;

[0021] Based on the session key and the key start and end sequence numbers, a key distribution message is generated and sent to the local OTN device.

[0022] In a fourth aspect, the present invention provides an OTN device, comprising:

[0023] A key application module, configured to apply for a session key from the quantum key distribution network and associate the session key with a corresponding encryption policy;

[0024] The payload encryption and decryption module is configured to divide the frame structure of any layer in the optical path layer into an overhead area and a payload area, and, when the current sending OTN device supports adding information to the overhead area, add the session key sequence number used for encrypting the current frame on the current port to the overhead area, encrypt the payload area of ​​the current frame using the session key based on the encryption policy, and then send the entire frame to the opposite end OTN device; and, when the current sending OTN device does not support adding information to the overhead area, encrypt the payload area of ​​the current frame using the session key based on the encryption policy, and then send the frame to the opposite end OTN device.

[0025] The key synchronization control module is used to periodically send session key synchronization messages to the opposite OTN device when the current sending OTN device does not support additional information in the overhead area.

[0026] In a fifth aspect, the present invention provides an OTN device, comprising:

[0027] A key application module is used to receive the session key issued by the quantum key distribution network and associate the session key with the corresponding encryption policy;

[0028] The key synchronization control module is used to obtain the session key sequence number used for encrypting the incoming traffic of the current port from the key synchronization message sent by the opposite OTN device when the current receiving OTN device does not support additional information in the overhead area;

[0029] The payload encryption and decryption module is used to obtain the session key sequence number used for encrypting the current frame of the port's inbound traffic from the overhead area or from the key synchronization message sent by the opposite OTN device, and obtain the session key sequence number associated with the encryption policy based on the session key sequence number to decrypt the ciphertext information sent by the opposite OTN device.

[0030] In a sixth aspect, the present invention provides a key controller, comprising:

[0031] The key application receiving module is used to receive the key application message sent by the local OTN device;

[0032] The key application verification module is used to verify that the key application message is passed and then query the cryptographic service platform for the QKD node information of the opposite OTN device;

[0033] The session key acquisition module is used to obtain the session key and key start and end sequence numbers from the key pool corresponding to the QKD link between the QKD node of the local OTN device and the QKD node of the opposite OTN device, and report the key start and end sequence numbers to the cryptographic service platform so that the cryptographic service platform sends the key start and end sequence numbers and the QKD node information of the local OTN device to the key controller corresponding to the opposite OTN device;

[0034] The key distribution message generation module is used to generate a key distribution message based on the session key and the key start and end sequence numbers and send the message to the local OTN device.

[0035] In a seventh aspect, the present invention provides an OTN encryption and decryption communication system based on quantum key distribution, the system comprising: a first OTN device and a second OTN device, the first OTN device being connected to a first key controller via a first OTN controller, the second OTN device being connected to a second key controller via a second OTN controller, the first key controller and the second key controller being both connected to a cryptographic service platform, and the first key controller and the second key controller being both connected to a quantum key distribution network;

[0036] The first key controller and the second key controller are configured to obtain or transmit a session key to an OTN device within the domain according to information of the opposite OTN device provided by the cryptographic service platform;

[0037] The first OTN controller and the second OTN controller are configured to establish a key distribution network channel between the OTN equipment in their respective domains and the corresponding key controllers;

[0038] The first OTN device is configured to encrypt the payload using the OTN encryption communication method based on quantum key distribution to obtain ciphertext information;

[0039] The second OTN device is configured to decrypt the ciphertext information sent by the first OTN device using the OTN decryption communication method based on quantum key distribution as described above.

[0040] The advantages of the present invention are:

[0041] (1) The present invention obtains session keys from a quantum key distribution network and divides the frame structure of any layer in the optical path layer into an overhead area and a payload area. Based on the encryption strategy, the session key is used to encrypt the payload of the user load at any level of the optical path layer. The present invention supports two methods of session key synchronization: frame additional information and management channel notification, thereby improving the reliability of OTN communication. Moreover, the session keys for encrypted communication between OTN devices in different domains are distributed through the QKD network, which has high security and communication efficiency and simple management and deployment.

[0042] (2) The OTN equipment and key controller are pre-filled with a large-capacity master key generated by the quantum key distribution network QKD, realizing a true one-time key distribution protection process, and enhancing the security of the entire system from the top level.

[0043] (3) Establish a master key pool and a session key pool in the OTN equipment to store the master key and session key respectively, reduce the frequency of key application and update, and improve communication efficiency.

[0044] (4) A three-layer structure consisting of a cryptographic service platform, a key controller, and an encryption communication module is adopted, corresponding to the management plane, control plane, and data plane structure of the software-defined network (SDN), to implement the idea of ​​software-defined cryptography.

[0045] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] FIG1 is a schematic flow chart of an OTN encryption communication method based on quantum key distribution proposed in the first embodiment of the present invention;

[0047] FIG2 is a flow chart of an OTN decryption communication method based on quantum key distribution proposed in the second embodiment of the present invention; FIG3 is a flow chart of a session key distribution method proposed in the third embodiment of the present invention;

[0048] 4 is a schematic structural diagram of an OTN device proposed in a fourth embodiment of the present invention;

[0049] FIG5 is a schematic structural diagram of a key controller proposed in a fifth embodiment of the present invention;

[0050] FIG6 is a schematic structural diagram of an OTN encryption and decryption communication system based on quantum key distribution proposed in a seventh embodiment of the present invention;

[0051] FIG7 is a schematic diagram of the workflow of an OTN encryption and decryption communication system based on quantum key distribution proposed in the seventh embodiment of the present invention. DETAILED DESCRIPTION

[0052] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0053] Example 1

[0054] As shown in FIG1 , the first embodiment of the present invention discloses an OTN encryption communication method based on quantum key distribution, which is applied to a sender OTN device. The method includes the following steps:

[0055] S101, applying for a session key from a quantum key distribution network, and associating the session key with a corresponding encryption policy;

[0056] S102, dividing the frame structure of any layer in the optical path layer into an overhead area and a payload area;

[0057] It should be noted that this embodiment uses the native OTN technology to divide the overhead area and the payload area, and sets whether the OTN device supports additional information in the overhead area through system settings, specifically, k 、ODU k and OPU k The frame structure is divided into overhead area and payload area.

[0058] S103: When the current sending OTN device supports adding information to the overhead area, add the session key sequence number used for encrypting the current frame on the current port to the overhead area, encrypt the payload area of ​​the current frame using the session key based on the encryption policy, and then send the entire frame to the opposite end OTN device;

[0059] S104: When the current sending OTN device does not support adding information to the overhead area, encrypt the payload area of ​​the current frame using the session key based on the encryption policy and send it to the opposite OTN device, and periodically send a session key synchronization message to the opposite OTN device.

[0060] This embodiment obtains session keys from a quantum key distribution network and distributes session keys for encrypted communication between OTN devices in different domains through the QKD network. This embodiment has high security and communication efficiency, and is simple to manage and deploy. The frame structure of any layer in the optical path layer (OCh) is divided into an overhead area and a payload area. Based on the encryption strategy, the session key is used to encrypt the payload of user loads at any level of the optical path layer, thereby achieving end-to-end direct encrypted communication between OTN device nodes in different security domains. Session key synchronization is supported through both frame additional information and management channel notification. The overhead area of ​​each OTN layer carries key information, or key synchronization is performed through a dedicated management channel. This ensures key synchronization, thereby improving the reliability of encrypted communication while causing zero intrusion into OTN native services, thereby improving the reliability of OTN communication.

[0061] In one embodiment, the optical path layer OCh includes an optical path transmission unit OTU k, Optical Channel Data Unit ODU k and Optical Path Payload Unit (OPU) k , k takes different values ​​to represent different transmission rates, the step S102: encrypting the payload area of ​​the current frame using the session key based on the encryption strategy, includes the following steps:

[0062] The OTU is encrypted using the session key based on the encryption strategy k 、ODU k and OPU k The payload of the user load in the payload area corresponding to any unit is transparently encrypted.

[0063] It should be noted that this embodiment sets the OTU according to the system settings. k 、ODU k and OPU k The payload of any layer of user load is transparently encrypted. The encryption mode adopts CBC (integer multiple of algorithm block) + CFB (remainder beyond integer multiple of algorithm block). No additional data is added, no impact is made on OTN services, and compatibility is good.

[0064] In one embodiment, the session key synchronization message includes the session key serial number currently used by the sender's OTN device port, identifiers of both communicating OTN devices, port identifiers of both communicating OTN devices, a timestamp of the sender's OTN device, and a key check value.

[0065] Specifically, the key check value is calculated as follows: SM3_HMAC(Key Seq ,Seq|IDi|IDr|Port_i|Port_r|timestamp)

[0066] Among them, IDi is the initiator OTN device identifier, IDr is the receiver OTN device identifier, Port_i is the port identifier of the initiator OTN device, Port_r is the port identifier of the receiver OTN device, timestamp is the timestamp of the initiator OTN device, Key Seq Represents the session key with sequence number Seq, where Seq is the session key sequence number, | is the byte string connector, and SM3_HMAC(Key, X) represents performing a cryptographic hash operation on X using the cryptographic hash algorithm SM3 with the key Key.

[0067] In one embodiment, the session key synchronization message is transmitted via a management control channel between OTN devices of both communicating parties.

[0068] It should be noted that a management control channel and an OTN encryption channel are set up between the initiator OTN device and the receiver OTN device. If the OTN device supports adding information in the overhead area, the session key number used for encrypting the current frame of the current port is added to the overhead area; if the OTN device does not support adding information in the overhead area, a key synchronization message is regularly sent to the OTN device at the opposite end of the current port through the management and operation channel to transmit the session key number. By setting up support for frame additional information and management channel notification of two key synchronization methods, the reliability of OTN communication is improved.

[0069] In one embodiment, the sending OTN device stores an encryption policy issued by a cryptographic service platform, wherein the encryption policy includes port identifiers, encryption algorithms, and clear and secret attributes of the OTN devices of both communicating parties.

[0070] It should be understood that both the sending OTN device and the receiving OTN device store the encryption policy issued by the cryptographic service platform.

[0071] Specifically, the encryption policy includes the device and port identification of both parties, encryption algorithm, and properties such as clear and secret communication. For example:

[0072] OTN1: Port 1<—>OTN2: Port 1 uses SM4 algorithm for encryption;

[0073] OTN1: port 2 <—> OTN3: port 1 is directly open;

[0074] OTN2: Port 2<—>OTN3: Port 2 uses AES algorithm for encryption;

[0075] …

[0076] In actual applications, the cryptographic service platform establishes a mapping relationship between OTN devices and QKD nodes, establishes a connection topology between encryption ports of different OTN devices and configures corresponding encryption policies, and sends the encryption policies of the OTN devices to the key controller and further to the OTN devices through the network channel between the key controller and the OTN controller.

[0077] In one embodiment, the step S101 of applying for a session key from a quantum key distribution network specifically includes the following steps:

[0078] S111, sending a key application message to the connected key controller;

[0079] It should be noted that the OTN device is connected to the corresponding key controller through the OTN controller, and the key controller is connected to the cryptographic service platform and the quantum key distribution network QKD respectively.

[0080] Among them, the quantum key distribution network QKD includes quantum network nodes and quantum network link control centers, which realize services such as quantum key generation, quantum key relay, and quantum key provision;

[0081] Quantum network nodes, i.e., QKD nodes, store generated quantum keys, receive key requests for key distribution, and provide key injection services through key controllers or directly;

[0082] Quantum network link control center: can establish quantum key distribution and relay links between nodes according to quantum network node ID.

[0083] S112. Receive a key distribution message returned by the connected key controller, where the key distribution message is obtained by the key controller after verifying that the key application message is passed, obtaining a session key from the QKD network and encrypting it using a randomly selected master key.

[0084] The key controller corresponding to the initiator OTN device forwards the key distribution message to the initiator OTN device through the network connection channel between the key controller and the OTN controller.

[0085] This embodiment applies for and distributes keys based on QKD. The encrypting and decrypting parties do not obtain keys from the same KM, but instead use QKD's cross-domain key transmission to obtain the same key from KMs distributed in different regions connected to the QKD network.

[0086] In one embodiment, a master key pool is provided in both the sending OTN device and the key controller, and a master key is stored in the master key pool.

[0087] Specifically, large-capacity secure media such as smart password keys, secure SIM cards, secure TF cards, or encrypted files can be used, or transmitted online through secure channels (such as TLS), to fill the OTN devices of both communicating parties with large-capacity quantum master keys and establish their own master key pools. The key controllers corresponding to the OTN devices of both communicating parties also establish master key pools for their respective OTN devices.

[0088] Accordingly, the step S111: sending a key application message to the connected key controller specifically includes:

[0089] According to the encryption policy of the sender's OTN device, a key application message is sent to the key controller to which it is connected. The key application message uses the master key Key randomly selected from the master key pool corresponding to the sender's OTN device. IDk For encryption protection, the content of the key application message is as follows:

[0090] OTN equipment identifier of the initiator IDi + OTN equipment identifier of the receiver IDr + master key identifier IDk + number of session keys applied for Nk + SM3_HMAC (Key IDk , IDi|IDr|IDk).

[0091] In one embodiment, the key distribution message is obtained by the key controller using a master key in its own master key pool to verify that the key application message is passed, obtaining a session key and a session key sequence number from the QKD network, and encrypting them using a randomly selected master key;

[0092] The session key is obtained from the key pool corresponding to the QKD link between the QKD node belonging to the sender's OTN device and the QKD node belonging to the opposite end's OTN device.

[0093] Specifically, the initiator OTN device forwards the session key application to the initiator key controller through the network connection channel between the initiator OTN controller and the initiator key controller. The initiator key controller uses the IDk identifier to select the corresponding master key from its master key pool to calculate SM3_HMAC. After verification, the initiator key controller queries the QKD node information to which the receiver OTN device identifier IDr belongs to the cryptographic service platform. The initiator key controller obtains Nk session keys from the key pool corresponding to the QKD link between the QKD node to which the initiator OTN device belongs and the QKD node of the receiver OTN device and reports the key start and end sequence numbers (Seq_start, Seq_end) to the cryptographic service platform.

[0094] The initiator's key controller generates a session key distribution message based on the session key and randomly selects a master key from its corresponding master key pool for encryption. The key distribution message is protected by the randomly selected master key and has the following content:

[0095] OTN equipment identifier of the initiator IDi + OTN equipment identifier of the receiver IDr + master key identifier IDk_i + number of keys applied for Nk + Seq_Start + Seq_end + SM4_ENC (Key IDk_i , Key1|Key2…|Key Nk )+SM3_HMAC(Key IDk_i ,IDi|IDr|IDk|Seq_start|Seq_end)

[0096] Wherein, SM4_ENC(Key, X) indicates that an encryption operation is performed on X using the key Key and the block cipher algorithm SM4.

[0097] In one embodiment, after receiving the key distribution message returned by the connected key controller in step S112, the method further includes:

[0098] Decrypt the key distribution message using the master key in the master key pool corresponding to the sender's OTN device to obtain the session key;

[0099] The session key is stored in a session key pool, and the session key is associated with a corresponding encryption policy.

[0100] It should be noted that the initiator OTN device selects the corresponding master key from its own corresponding master key pool based on the master key identifier IDk_i to decrypt the session key distribution message, obtains the session key, stores the session key in the session key pool, and adds a connection pointing to the block session key for the corresponding encryption policy.

[0101] This embodiment uses a large-capacity master key generated by a quantum key distribution network (QKD) and injects it into the master key pool in the OTN device and key controller, achieving a true one-time key distribution protection process, enhancing the security of the entire system from the top level. The QKD network is used to distribute session keys for encrypted communication between OTN devices in different domains, which has high security and communication efficiency and simple management and deployment. In addition, by establishing a key pool in the OTN device to store the master key and session key, the frequency of key application and update is reduced, thereby improving communication efficiency.

[0102] In one embodiment, the method further includes periodically updating a session key associated with the encryption policy, specifically by:

[0103] Increment the sequence number of the session key used for payload encryption by 1;

[0104] When the key sequence number exceeds the upper limit of the sequence number of the session key distributed by the key, the session key distribution process is re-triggered to update the session key.

[0105] Specifically, the session key sequence number is increased by 1 and used for OTN outbound traffic encryption. When the key sequence number exceeds the upper limit of the key distribution sequence number, that is, the above-mentioned Seq_end, a key application is performed to trigger the above-mentioned key distribution process.

[0106] Example 2

[0107] As shown in FIG2 , the second embodiment of the present invention discloses an OTN decryption communication method based on quantum key distribution, which is applied to a receiving OTN device. The method includes the following steps:

[0108] S201, receiving a session key issued by a quantum key distribution network, and associating the session key with a corresponding encryption policy;

[0109] S202: When the current receiving OTN device supports adding information to the overhead area, obtain the session key sequence number used for encrypting the current frame of the port inbound traffic from the overhead area;

[0110] S203: When the current receiving OTN device does not support adding information in the overhead area, obtain the session key sequence number used for encrypting the current port's inbound traffic from the key synchronization message sent by the opposite OTN device;

[0111] S204: Obtain a session key associated with the encryption policy based on the session key sequence number, and decrypt the ciphertext information sent by the opposite OTN device.

[0112] In this embodiment, the receiving OTN device decrypts the payload of user loads at any layer of the optical path according to system settings. If the receiving OTN device supports adding information to the overhead area, it obtains the session key sequence number used for encrypting the current port's incoming traffic frame from the overhead area, and obtains the session key from the session key block pointed to by the port's encryption policy for decryption, thus preventing key asynchrony. If the receiving OTN device does not support adding information to the overhead area, it obtains the session key sequence number used for encrypting the port's incoming traffic from the received key synchronization message, and obtains the session key from the session key block pointed to by the port's encryption policy for decryption, thus resolving key asynchrony in the shortest possible time. Supporting both frame-added information and management channel notification for key synchronization improves OTN communication reliability.

[0113] In one embodiment, the receiving OTN device stores an encryption policy issued by a cryptographic service platform, wherein the encryption policy includes port identifiers, encryption algorithms, and clear and secret attributes of the OTN devices of both communicating parties.

[0114] In this embodiment, OTU is configured according to the system settings. k 、ODU k and OPU k The payload of any level of user load is transparently decrypted. The decryption mode adopts CBC (integer multiple of algorithm block) + CFB (remainder beyond integer multiple of algorithm block) without adding any extra data.

[0115] In one embodiment, the session key synchronization message includes the session key serial number currently used by the sender's OTN device port, identifiers of both communicating OTN devices, port identifiers of both communicating OTN devices, a timestamp of the sender's OTN device, and a key check value.

[0116] Specifically, the key check value is calculated as follows:

[0117] SM3_HMAC(Key Seq,Seq|IDi|IDr|Port_i|Port_r|timestamp)

[0118] Among them, IDi is the initiator OTN device identifier, IDr is the receiver OTN device identifier, Port_i is the port identifier of the initiator OTN device, Port_r is the port identifier of the receiver OTN device, timestamp is the timestamp of the initiator OTN device, Key Seq Represents the session key with sequence number Seq, where Seq is the session key sequence number, | is the byte string connector, and SM3_HMAC(Key, X) represents performing a cryptographic hash operation on X using the cryptographic hash algorithm SM3 with the key Key.

[0119] In one embodiment, the session key synchronization message is transmitted via a management control channel between OTN devices of both communicating parties.

[0120] It should be noted that a management control channel and an OTN encryption channel are set up between the initiator OTN device and the receiver OTN device. If the OTN device supports adding information in the overhead area, the session key sequence number used for encrypting the current frame of the current port is added to the overhead area; if the OTN device does not support adding information in the overhead area, a key synchronization message is regularly sent to the OTN device at the opposite end of the port through the management and operation channel to transmit the session key sequence number. By setting up support for frame additional information and management channel notification of two key synchronization methods, the reliability of OTN communication is improved.

[0121] In one embodiment, both the sending OTN device and the receiving OTN device store an encryption policy issued by the cryptographic service platform. The encryption policy includes port identifiers, encryption algorithms, and clear and secret attributes of the OTN devices of both communicating parties.

[0122] It should be understood that both the sending OTN device and the receiving OTN device store the encryption policy issued by the cryptographic service platform.

[0123] Specifically, the encryption policy includes the device and port identification of both parties, encryption algorithm, and properties such as clear and secret communication. For example:

[0124] OTN1: Port 1<—>OTN2: Port 1 uses SM4 algorithm for encryption;

[0125] OTN1: port 2 <—> OTN3: port 1 is directly open;

[0126] OTN2: Port 2<—>OTN3: Port 2 uses AES algorithm for encryption;

[0127] …

[0128] In actual applications, the cryptographic service platform establishes a mapping relationship between OTN devices and QKD nodes, establishes a connection topology between encryption ports of different OTN devices and configures corresponding encryption policies, and sends the encryption policies of the OTN devices to the key controller and further to the OTN devices through the network channel between the key controller and the OTN controller.

[0129] In one embodiment, the method further comprises the following steps:

[0130] When it is determined that key desynchronization occurs, the receiving OTN device acts as an initiator to re-trigger the session key distribution process;

[0131] The situations in which key desynchronization occurs include: a session key sequence obtained from the overhead area has no corresponding session key, a session key sequence number obtained from the key synchronization message has no corresponding session key, or the key synchronization message fails to be verified.

[0132] In one embodiment, step S201: receiving a session key issued by a quantum key distribution network includes the following steps:

[0133] Receive the key distribution message sent by the key controller connected to the receiving OTN device, where the session key carried in the key distribution message is the session key start and end sequence numbers obtained by the key controller based on the opposite OTN device sent by the cryptographic service platform and the QKD node information corresponding to the opposite OTN device, and obtain the session key corresponding to the session key start and end sequence numbers from the key pool corresponding to the QKD link between the QKD node belonging to the receiving OTN device and the QKD node belonging to the opposite OTN device.

[0134] In one embodiment, the receiving OTN device and the key controller connected thereto are both provided with a master key pool, wherein the master key pool stores a master key, and the key distribution message is a message using the master key Key in the master key pool corresponding to the key controller. IDk_r Encrypted, the specific content is:

[0135] Initiator OTN equipment identifier IDi+Receiver OTN equipment identifier IDr+Master key identifier IDk_r+Application key quantity Nk+Seq_Start+Seq_end+SM4_ENC(Key IDk_r , Key1|Key2…|Key Nk )+SM3_HMAC(Key IDk_r ,IDi|IDr|IDk|Seq_start|Seq_end)

[0136] In one embodiment, after receiving the key distribution message sent by the key controller to which the receiving OTN device is connected, the method further includes the following steps:

[0137] Decrypting the key distribution message using a randomly corresponding master key from a master key pool corresponding to the receiving OTN device to obtain the session key;

[0138] The session key is stored in a session key pool, and the session key is associated with a corresponding encryption policy.

[0139] Example 3

[0140] As shown in FIG3 , a third embodiment of the present invention discloses a session key distribution method, which is applied to a key controller. The method includes the following steps:

[0141] S301, receiving a key application message sent by the local OTN device;

[0142] S302: After verifying that the key application message is passed, query the cryptographic service platform for the QKD node information of the peer OTN device;

[0143] S303: Obtain the session key and key start and end sequence numbers from the key pool corresponding to the QKD link between the QKD node of the local OTN device and the QKD node of the opposite OTN device, and report the key start and end sequence numbers to the cryptographic service platform so that the cryptographic service platform sends the key start and end sequence numbers and the QKD node information of the local OTN device to the key controller corresponding to the opposite OTN device;

[0144] S304: Generate a key distribution message based on the session key and the key start and end sequence numbers and send it to the local OTN device.

[0145] This embodiment distributes session keys for encrypted communication between OTN devices in different domains through the QKD network, which has high security and communication efficiency and simple management and deployment.

[0146] In one embodiment, a master key pool is set in both the local OTN device and the peer OTN device, and the master key is stored in the master key pool;

[0147] The key application message is encrypted by randomly selecting a master key from its corresponding master key pool by the local OTN device. The content of the key application message is:

[0148] OTN equipment identifier of the initiator IDi + OTN equipment identifier of the receiver IDr + master key identifier IDk + number of keys applied for Nk + SM3_HMAC (Key IDk , IDi|IDr|IDk).

[0149] In one embodiment, the step S302: after verifying that the key application message is passed, querying the cryptographic service platform for the QKD node information of the peer OTN device includes the following steps:

[0150] Verify the key application message based on a corresponding master key selected from a master key pool corresponding to a key controller connected to the local OTN device;

[0151] After verification, query the cryptographic service platform for the QKD node information of the peer OTN device;

[0152] The cryptographic service platform stores the mapping relationship between OTN devices and QKD nodes, as well as the connection topology of encryption ports between different OTN devices and the corresponding encryption strategy.

[0153] It should be noted that this embodiment uses a large-capacity master key generated by the quantum key distribution network QKD and pre-fills it into the master key pool of the key controller and OTN equipment to encrypt key application messages and session key distribution messages, realizing a true one-time key distribution protection process, and enhancing the security of the entire system from the top level.

[0154] In one embodiment, generating a key distribution message based on the session key and the key start and end sequence numbers and sending the message to the local OTN device includes:

[0155] Generate a key distribution message based on the session key and the key start and end sequence numbers;

[0156] The key distribution message is encrypted using the master key in the corresponding master key pool and then sent to the local OTN device.

[0157] Specifically, the key distribution message is protected by a randomly selected master key and is pushed to the recipient OTN device through the recipient OTN controller. The content is as follows:

[0158] OTN equipment identifier of the initiator IDi + OTN equipment identifier of the receiver IDr + master key identifier IDk_i + number of keys applied for Nk + Seq_Start + Seq_end + SM4_ENC (Key IDk_i ,Key1|Key2…|KeyNk)+SM3_HMAC(Key IDk_i , IDi|IDr|IDk|Seq_start|Seq_end).

[0159] Example 4

[0160] As shown in FIG4 , a fourth embodiment of the present invention discloses an OTN device, including:

[0161] A key application module 11 is used to apply for a session key from a quantum key distribution network and associate the session key with a corresponding encryption policy;

[0162] The payload encryption and decryption module 12 is configured to divide the frame structure of any layer in the optical path layer into an overhead area and a payload area, and, when the current sending OTN device supports adding information to the overhead area, add the session key sequence number used for encrypting the current frame on the current port to the overhead area, encrypt the payload area of ​​the current frame using the session key based on the encryption policy, and then send the entire frame to the opposite end OTN device; and, when the current sending OTN device does not support adding information to the overhead area, encrypt the payload area of ​​the current frame using the session key based on the encryption policy, and then send the frame to the opposite end OTN device.

[0163] The key synchronization control module 13 is configured to periodically send a session key synchronization message to the opposite OTN device when the current sending OTN device does not support adding information in the overhead area.

[0164] This embodiment obtains session keys from a quantum key distribution network and distributes session keys for encrypted communication between OTN devices in different domains through the QKD network. This approach offers high security and communication efficiency, and is simple to manage and deploy. The frame structure of any layer in the optical path layer (OCh) is divided into an overhead area and a payload area. The session key is used to encrypt the payload of user loads at any level of the optical path layer based on an encryption strategy, enabling end-to-end direct encrypted communication between OTN device nodes in different security domains. Session key synchronization is supported through both frame additional information and management channel notification, improving the reliability of OTN communications.

[0165] In one embodiment, the optical path layer includes an optical path transmission unit OTU k , Optical Channel Data Unit ODU k and Optical Path Payload Unit (OPU) k The payload encryption and decryption module 12 is used to use the session key to encrypt the OTU based on the encryption strategy. k 、ODU k and OPU k The payload of the user load in the payload area corresponding to any unit is transparently encrypted.

[0166] In one embodiment, the session key synchronization message includes the session key serial number currently used by the sender's OTN device port, identifiers of both communicating OTN devices, port identifiers of both communicating OTN devices, a timestamp of the sender's OTN device, and a key check value.

[0167] In one embodiment, the session key synchronization message is transmitted via a management control channel between OTN devices of both communicating parties.

[0168] In one embodiment, the sending OTN device stores an encryption policy issued by a cryptographic service platform, wherein the encryption policy includes port identifiers, encryption algorithms, and clear and secret attributes of the OTN devices of both communicating parties.

[0169] In one embodiment, the key application module 11 includes:

[0170] A key application unit, configured to send a key application message to a connected key controller;

[0171] The key distribution message receiving unit is used to receive the key distribution message returned by the connected key controller. The key distribution message is obtained by the key controller after verifying that the key application message is passed, obtaining the session key from the QKD network and encrypting it using a randomly selected master key.

[0172] In one embodiment, the sending OTN device and the key controller are both provided with a master key pool, and the master key is stored in the master key pool; the key application module 11 is further used to: send a key application message to the key controller connected to it according to the encryption policy of the sending OTN device, and the key application message uses a master key Key randomly selected from the master key pool corresponding to the sending OTN device. IDk Encryption protection.

[0173] In one embodiment, the key distribution message is obtained by the key controller using a master key in its own master key pool to verify that the key application message is passed, obtaining a session key and a session key sequence number from the QKD network, and encrypting them using a randomly selected master key;

[0174] The session key is obtained from the key pool corresponding to the QKD link between the QKD node belonging to the sender's OTN device and the QKD node belonging to the opposite end's OTN device.

[0175] In one embodiment, the key distribution message receiving unit is configured to:

[0176] Decrypt the key distribution message using the master key in the master key pool corresponding to the sender's OTN device to obtain the session key;

[0177] The session key is stored in a session key pool, and the session key is associated with a corresponding encryption policy.

[0178] In one embodiment, the OTN device further includes a first key update module configured to:

[0179] Increment the sequence number of the session key used for payload encryption by 1;

[0180] When the key sequence number exceeds the upper limit of the sequence number of the session key for key distribution, the key application module 22 is re-triggered to perform the session key distribution process and update the session key.

[0181] It should be noted that other embodiments or implementation methods of the OTN device of the present invention can refer to the above method.

[0182] Example 1 is not repeated here.

[0183] Example 5

[0184] As shown in FIG4 , a fifth embodiment of the present invention discloses an OTN device, including:

[0185] The key application module 11 is used to receive the session key issued by the quantum key distribution network and associate the session key with the corresponding encryption policy;

[0186] The key synchronization control module 13 is configured to obtain the session key sequence number used for encrypting the inbound traffic of the port from the key synchronization message sent by the opposite OTN device when the current receiving OTN device does not support additional information in the overhead area;

[0187] The payload encryption and decryption module 12 is configured to obtain the session key sequence number used for encrypting the current port's incoming traffic frame from the overhead area or from the key synchronization message sent by the opposite OTN device, and obtain the session key sequence number associated with the encryption policy based on the session key sequence number to decrypt the ciphertext information sent by the opposite OTN device.

[0188] In one embodiment, the session key synchronization message includes the session key serial number currently used by the sender's OTN device port, identifiers of both communicating OTN devices, port identifiers of both communicating OTN devices, a timestamp of the sender's OTN device, and a key check value.

[0189] In one embodiment, the session key synchronization message is transmitted via a management control channel between OTN devices of both communicating parties.

[0190] In one embodiment, the receiving OTN device stores an encryption policy issued by a cryptographic service platform, wherein the encryption policy includes port identifiers, encryption algorithms, and clear and secret attributes of the OTN devices of both communicating parties.

[0191] In one embodiment, the OTN device further includes a second key update module configured to:

[0192] When it is determined that key desynchronization occurs, the receiving OTN device acts as an initiator to re-trigger the session key distribution process;

[0193] The situations in which key desynchronization occurs include: a session key sequence obtained from the overhead area has no corresponding session key, a session key sequence number obtained from the key synchronization message has no corresponding session key, or the key synchronization message fails to be verified.

[0194] In one embodiment, the key application module 11 is further configured to:

[0195] Receive the key distribution message sent by the key controller connected to the receiving OTN device, where the session key carried in the key distribution message is the session key start and end sequence numbers obtained by the key controller based on the opposite OTN device sent by the cryptographic service platform and the QKD node information corresponding to the opposite OTN device, and obtain the session key corresponding to the session key start and end sequence numbers from the key pool corresponding to the QKD link between the QKD node belonging to the receiving OTN device and the QKD node belonging to the opposite OTN device.

[0196] In one embodiment, the receiving OTN device and the key controller connected thereto are both provided with a master key pool, the master key pool storing a master key, and the key distribution message is encrypted using the master key in the master key pool corresponding to the key controller; the key application module 11 is further specifically configured to:

[0197] Decrypting the key distribution message using a randomly corresponding master key from a master key pool corresponding to the receiving OTN device to obtain the session key;

[0198] The session key is stored in a session key pool, and the session key is associated with a corresponding encryption policy.

[0199] In this embodiment, a master key pool and a session key pool are established in the OTN equipment. The master key pool stores a large number of master keys generated and pre-filled by the quantum key distribution network, and the session key pool stores session keys distributed by the quantum key distribution network. The key pool is established to store the master keys and session keys, thereby reducing the frequency of key application and update and improving communication efficiency.

[0200] It should be noted that other embodiments or implementation methods of the OTN device of the present invention can refer to the above method.

[0201] Example 2 is not repeated here.

[0202] Example 6

[0203] As shown in FIG5 , the sixth embodiment of the present invention discloses a key controller, which includes:

[0204] The key application receiving module 21 is used to receive the key application message sent by the local OTN device;

[0205] The key application verification module 22 is used to verify that the key application message is passed and then query the cryptographic service platform for the QKD node information of the opposite OTN device;

[0206] The session key acquisition module 23 is configured to obtain the session key and key start and end sequence numbers from the key pool corresponding to the QKD link between the QKD node of the local OTN device and the QKD node of the opposite OTN device, and report the key start and end sequence numbers to the cryptographic service platform so that the cryptographic service platform sends the key start and end sequence numbers and the QKD node information of the local OTN device to the key controller corresponding to the opposite OTN device;

[0207] The key distribution message generation module 24 is configured to generate a key distribution message based on the session key and the key start and end sequence numbers, and send the message to the local OTN device.

[0208] In one embodiment, a master key pool is set in both the local OTN device and the peer OTN device, and the master key is stored in the master key pool;

[0209] The key application message is obtained by encrypting a master key randomly selected by the local OTN device from its corresponding master key pool.

[0210] In one embodiment, the key application verification module 22 is specifically configured to:

[0211] Verify the key application message based on a corresponding master key selected from a master key pool corresponding to a key controller connected to the local OTN device;

[0212] After verification, query the cryptographic service platform for the QKD node information of the peer OTN device;

[0213] The cryptographic service platform stores the mapping relationship between OTN devices and QKD nodes, as well as the connection topology of encryption ports between different OTN devices and the corresponding encryption strategy.

[0214] In one embodiment, the key distribution message generation module 24 is configured to:

[0215] Generate a key distribution message based on the session key and the key start and end sequence numbers;

[0216] The key distribution message is encrypted using the master key in the corresponding master key pool and then sent to the local OTN device.

[0217] It should be noted that other embodiments or implementation methods of the key controller of the present invention can refer to the above method.

[0218] Example 3 is not repeated here.

[0219] Example 7

[0220] As shown in FIG6 , the seventh embodiment of the present invention discloses an OTN encryption and decryption communication system based on quantum key distribution. The system includes: a first OTN device and a second OTN device, wherein the first OTN device is connected to a first key controller via a first OTN controller, and the second OTN device is connected to a second key controller via a second OTN controller. The first key controller and the second key controller are both connected to a cryptographic service platform, and the first key controller and the second key controller are both connected to a quantum key distribution network.

[0221] The first key controller and the second key controller are configured to obtain or transmit a session key to an OTN device within the domain according to information of the opposite OTN device provided by the cryptographic service platform;

[0222] The first OTN controller and the second OTN controller are configured to establish a key distribution network channel between the OTN equipment in their respective domains and the corresponding key controllers;

[0223] The first OTN device is configured to encrypt the payload using the OTN encryption communication method based on quantum key distribution as described in the first embodiment above to obtain ciphertext information;

[0224] The second OTN device is configured to decrypt the ciphertext information sent by the first OTN device using the OTN decryption communication method based on quantum key distribution as described in the second embodiment above.

[0225] Specifically, the key controller provided in this embodiment is used to synchronously transmit through the QKD device or obtain the quantum key from the QKD device and transmit it (through the OTN controller) to the OTN device in the domain according to the peer OTN device information provided by the CSP.

[0226] OTN controller: A network component used to operate, manage, and maintain OTN devices. It runs a key distribution agent and establishes a key distribution network channel between OTN devices within the controller's domain and the key controller.

[0227] OTN equipment generally refers to the OTN equipment on the user access side. It provides OTN channels by port and runs the payload encryption and decryption module to encrypt (outbound) and decrypt (inbound) the payload of OTUk / ODUk / OPUk at the port granularity. A master key pool is established on it to provide the master key used for session key distribution protection. A session key pool is established to provide the keys required for OTUk / ODUk / OPUk encryption and decryption. The key synchronization control module is run to verify the correctness of the key and perform key synchronization control. The key application module is run to apply for the corresponding session key from the key controller through the network channel of the OTN controller.

[0228] Cryptographic service platform: used to provide the mapping relationship between OTN devices and QKD nodes, establish the connection topology of encryption ports between different OTN devices, and configure and issue corresponding encryption policies.

[0229] Quantum key distribution network: includes quantum network nodes and quantum network link control center, realizing quantum key generation, quantum key relay, quantum key provision and other services;

[0230] Quantum network node (QKD node): stores the generated quantum key, receives key applications for key distribution, and provides key injection services through the key controller or directly;

[0231] Quantum network link control center: can establish quantum key distribution and relay links between nodes according to quantum network node ID.

[0232] It should be understood that the specific structural configuration of the OTN device and the key controller in this embodiment can be found in the contents described in the fourth to sixth embodiments above, and will not be repeated here.

[0233] Furthermore, as shown in FIG7 , the workflow of the OTN encryption and decryption communication system based on quantum key distribution proposed in this embodiment is as follows (hereinafter referred to as the initiator OTN device is the initiator of the key distribution process, and the receiver OTN device is the receiver of the key distribution process. In actual OTN encryption communication, both the first OTN device and the second OTN device are simultaneously the sender and the receiver):

[0234] (1) Initialization: Use large-capacity secure media or encrypted files or transmit them online through secure channels (such as TLS) to fill the OTN devices with large-capacity quantum master keys and establish their own master key pools. The corresponding key controller also establishes the master key pools of each OTN device.

[0235] (2) The cryptographic service platform establishes a mapping relationship between OTN devices and QKD nodes, establishes a connection topology between encryption ports of different OTN devices, and configures corresponding encryption policies. The encryption policies include the device and port identification, encryption algorithm, and other attribute settings such as clear and secret communication. For example:

[0236] OTN1: Port 1<—>OTN2: Port 1 uses SM4 algorithm for encryption;

[0237] OTN1: port 2 <—> OTN3: port 1 is directly open;

[0238] OTN2: Port 2<—>OTN3: Port 2 uses AES algorithm for encryption;

[0239] …

[0240] The cryptographic service platform sends the encryption policy of the OTN device to the key controller and further to the OTN device through the OTN controller.

[0241] (3) The key application module of the OTN device applies for a session key from the key controller according to the encryption policy. The key application message is protected by a randomly selected master key and has the following content:

[0242] OTN equipment identifier of the initiator IDi + OTN equipment identifier of the receiver IDr + master key identifier IDk + number of keys applied for Nk + SM3_HMAC (Key IDk , IDi|IDr|IDk)

[0243] (4) The initiator OTN controller forwards the session key application to the initiator key controller through the network connection channel between the controller and the key controller.

[0244] (5) The initiator's key controller uses the master key identified by IDk to calculate SM3_HMAC and verifies the information of the QKD node to which IDr belongs by querying the cryptographic service platform.

[0245] (6) The initiator key controller obtains Nk session keys from the key pool corresponding to the QKD link between the QKD node to which it belongs and the QKD node to which IDr belongs, and reports the key start and end sequence numbers (Seq_start, Seq_end) to the cryptographic service platform.

[0246] (7) The cryptographic service platform pushes the key start and end numbers obtained by IDi and the QKD node information corresponding to IDi to the receiving key controller.

[0247] (8) The receiving party key controller obtains Nk session keys corresponding to the key start and end sequence numbers (Seq_start, Seq_end) from the key pool corresponding to the QKD link between the QKD node to which it belongs and the QKD node to which IDi belongs.

[0248] (9) The initiator key controller sends the key distribution message to the initiator OTN device through the initiator OTN controller. The OTN device stores the received session key in the session key pool and associates it with the corresponding encryption policy (i.e., adds a link to the corresponding encryption policy pointing to the block session key). The key distribution message is protected by a randomly selected master key and has the following content:

[0249] OTN equipment identifier of the initiator IDi + OTN equipment identifier of the receiver IDr + master key identifier IDk_i + number of keys applied for Nk + Seq_Start + Seq_end + SM4_ENC (Key IDk_i , Key1|Key2…|Key Nk )+SM3_HMAC(Key IDk_i , IDi|IDr|IDk|Seq_start|Seq_end).

[0250] (10) The receiving party's key controller pushes the key distribution message to the receiving party's OTN device through the receiving party's OTN controller. The OTN device stores the received session key in the session key pool and associates it with the corresponding encryption policy (i.e., adds a link to the block session key for the corresponding encryption policy). The key distribution message is protected by a randomly selected master key and has the following content:

[0251] Initiator OTN equipment identifier IDi+Receiver OTN equipment identifier IDr+Master key identifier IDk_r+Application key quantity Nk+Seq_Start+Seq_end+SM4_ENC(Key IDk_r , Key1|Key2…|Key Nk )+SM3_HMAC(Key IDk_r , IDi|IDr|IDk|Seq_start|Seq_end).

[0252] (11) The OTN equipment uses the encryption strategy to call the payload encryption and decryption module and use the session key to encrypt the outgoing traffic of the OTN port. k / ODU k / OPU k The payload of any level of user load is encrypted. The encryption mode adopts CBC (integer multiple of algorithm block) + CFB (remainder beyond integer multiple of algorithm block) without adding any extra data.

[0253] OTU k / ODU k / OPU kThe frame structure is divided into an overhead area and a payload area. This solution transparently encrypts the payload area according to the system setting level (without adding additional data). If the OTN device supports adding information to the overhead area, the session key sequence number used for encrypting the frame of this port is added to the overhead area. If the OTN device does not support adding information to the overhead area, the key synchronization control module is enabled to regularly send a key synchronization message to the OTN device at the opposite end of the port through the management and operation channel. The message includes the session key sequence number Seq currently used by this device and this port, the device identifiers at both ends, the ports at both ends, the timestamp of this device, and the key check value. The key check value is calculated as follows:

[0254] SM3_HMAC(Key Seq , Seq|IDi|IDr|Port_i|Port_r|timestamp).

[0255] (12) The receiving OTN device uses the encryption policy to call the payload encryption and decryption module to decrypt the OTN port inbound traffic. k / ODU k / OPU k The payload of any level of user load is decrypted, and the decryption mode adopts CBC (integer multiple of algorithm block) + CFB (remainder beyond integer multiple of algorithm block).

[0256] If the OTN device supports and the system sets additional information in the overhead area, the session key sequence number used for encrypting the current frame of the port's inbound traffic is obtained from the overhead area, and the session key is obtained from the session key block pointed to by the port's encryption policy for decryption; if the OTN device does not support additional information in the overhead area, the session key sequence number used for encrypting the port's inbound traffic is obtained from the received key synchronization message, and the session key is obtained from the session key block pointed to by the port's encryption policy for decryption.

[0257] (13) Session key update: If the receiving OTN device does not have a corresponding key for the session key number obtained from the overhead area, or if the current session key number reported in the key synchronization message does not have a corresponding key or the verification fails, key desynchronization occurs. The OTN device that discovers the key desynchronization, which is the initiator, will apply for a key and trigger the key distribution process to refresh the session keys at both ends of the OTN communication.

[0258] The sending OTN device regularly updates the session key associated with the encryption policy, that is, increases the session key sequence number by 1 and uses it to encrypt OTN outbound traffic. When the key sequence number exceeds the upper limit of the key distribution sequence number, that is, the above-mentioned Seq_end, a key application is made, which triggers the above-mentioned key distribution process.

[0259] This embodiment deploys a quantum key distribution network (QKD) and a distributed key controller, running a key distribution agent on the OTN controller. A key pool is established on OTN devices, and cryptographic modules such as the key synchronization control module and the OTN payload encryption and decryption module are run. This enables end-to-end direct encrypted communication between OTN device nodes in different security domains. During the OTN payload encryption and decryption process, two key synchronization methods, frame appending information and management channel notification, are supported to improve reliability. During the key distribution process, session keys for encrypted communication between OTN devices in different domains are distributed over the QKD network, achieving high security and communication efficiency, while simplifying management and deployment. The large-capacity master key generated by the quantum key distribution network (QKD) ensures true one-time key distribution, enhancing the security of the entire system from the top level. OTN devices establish a key pool to store master and session keys, reducing the frequency of key requests and updates and improving communication efficiency. Furthermore, by adopting a three-layer architecture consisting of a cryptographic service platform, a key controller, and an encryption communication module, corresponding to the management, control, and data plane structures of SDN, the concept of software-defined cryptography is implemented.

[0260] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0261] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0262] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. An OTN encryption communication method based on quantum key distribution, characterized in that: Applied to a sender OTN device, the method includes: Apply for a session key from a quantum key distribution network and associate the session key with a corresponding encryption policy; Divide the frame structure of any layer in the optical path layer into an overhead area and a payload area; When the current sending OTN device supports adding additional information in the overhead area, the session key sequence number used for encrypting the current frame of the current port is added to the overhead area, and the payload area of ​​the current frame is encrypted using the session key based on the encryption strategy, and then the entire frame is sent to the opposite end OTN device; When the current sending OTN device does not support additional information in the overhead area, the payload area of ​​the current frame is encrypted using the session key based on the encryption strategy and then sent to the opposite OTN device, and a session key synchronization message is periodically sent to the opposite OTN device.

2. The OTN encryption communication method based on quantum key distribution according to claim 1, characterized in that: The optical path layer includes an optical path transmission unit OTU k , Optical Channel Data Unit ODU k Optical Path Payload Unit (OPU) k , encrypting the payload area of ​​the current frame using the session key based on the encryption strategy, comprising: The session key is used to encrypt OTU based on the encryption strategy. k 、ODU k and OPU k The payload of the user load in the payload area corresponding to any unit is transparently encrypted.

3. The OTN encryption communication method based on quantum key distribution according to claim 1, characterized in that: The session key synchronization message includes the session key serial number currently used by the sender's OTN device port, the identifiers of the OTN devices of both communicating parties, the port identifiers of the OTN devices of both communicating parties, the sender's OTN device timestamp and the key verification value.

4. The OTN encryption communication method based on quantum key distribution according to claim 1, characterized in that: The session key synchronization message is transmitted through the management control channel between the OTN devices of the communicating parties.

5. The OTN encryption communication method based on quantum key distribution according to claim 1, characterized in that: The sender OTN device stores an encryption policy issued by a cryptographic service platform, wherein the encryption policy includes port identifiers, encryption algorithms, and clear and secret attributes of the OTN devices of both communicating parties.

6. The OTN encryption communication method based on quantum key distribution according to claim 1, characterized in that: The applying for a session key from a quantum key distribution network comprises: Send a key request message to the connected key controller; Receive a key distribution message returned by the connected key controller, where the key distribution message is obtained by the key controller after verifying that the key application message is passed, obtaining a session key from the QKD network and encrypting it using a randomly selected master key.

7. The OTN encryption communication method based on quantum key distribution according to claim 6, characterized in that: The sender OTN device and the key controller are both provided with a master key pool, and the master key is stored in the master key pool; The sending of a key application message to the connected key controller comprises: According to the encryption policy of the sender OTN device, a key application message is sent to the key controller to which it is connected. The key application message uses the master key Key randomly selected from the master key pool corresponding to the sender OTN device. IDk Encryption protection.

8. The OTN encryption communication method based on quantum key distribution according to claim 6, characterized in that: The key distribution message is obtained by the key controller using the master key in its own master key pool to verify that the key application message is passed, and then obtaining the session key and the session key sequence number from the QKD network and encrypting them with the randomly selected master key; The session key is obtained from a key pool corresponding to a QKD link between a QKD node belonging to a sender's OTN device and a QKD node belonging to a peer's OTN device.

9. The OTN encryption communication method based on quantum key distribution according to claim 7, characterized in that: After receiving the key distribution message returned by the connected key controller, the method further includes: Decrypt the key distribution message using the master key in the master key pool corresponding to the sender OTN device to obtain the session key; The session key is stored in a session key pool, and the session key is associated with a corresponding encryption policy.

10. The OTN encryption communication method based on quantum key distribution according to claim 1, characterized in that: The method further comprises: Add 1 to the sequence number of the session key used for payload encryption; When the key sequence number exceeds the upper limit of the sequence number of the session key distributed by the key, the session key distribution process is re-triggered to update the session key.

11. An OTN decryption communication method based on quantum key distribution, characterized in that: Applied to a receiving OTN device, the method includes: Receive a session key issued by a quantum key distribution network, and associate the session key with a corresponding encryption strategy; When the current receiving OTN device supports adding information to the overhead area, the session key sequence number used for encrypting the current frame of the current port inbound traffic is obtained from the overhead area; When the current receiving OTN device does not support additional information in the overhead area, the session key sequence number used for encrypting the inbound traffic of the port is obtained from the key synchronization message sent by the opposite OTN device; A session key associated with the encryption policy is obtained based on the session key sequence number, and the ciphertext information sent by the opposite-end OTN device is decrypted.

12. The OTN decryption communication method based on quantum key distribution according to claim 11, characterized in that: The session key synchronization message includes the session key serial number currently used by the sender's OTN device port, the identifiers of the OTN devices of both communicating parties, the port identifiers of the OTN devices of both communicating parties, the sender's OTN device timestamp and the key verification value.

13. The OTN decryption communication method based on quantum key distribution according to claim 11, characterized in that: The session key synchronization message is transmitted through the management control channel between the OTN devices of the communicating parties.

14. The OTN decryption communication method based on quantum key distribution according to claim 11, characterized in that: The receiving OTN device stores an encryption policy issued by a cryptographic service platform, wherein the encryption policy includes port identifiers, encryption algorithms, and clear and secret attributes of the OTN devices of both communicating parties.

15. The OTN decryption communication method based on quantum key distribution according to claim 11, characterized in that: The method further comprises: When it is determined that key desynchronization occurs, the receiving OTN device, as the initiator, re-triggers the session key distribution process; The situations in which key desynchronization occurs include that the session key sequence obtained from the overhead area has no corresponding session key, or the session key sequence number obtained from the key synchronization message has no corresponding session key, or the key synchronization message verification fails.

16. The OTN decryption communication method based on quantum key distribution according to claim 11, characterized in that: The receiving a session key issued by a quantum key distribution network comprises: Receive a key distribution message sent by a key controller connected to the receiving OTN device, where the session key carried in the key distribution message is the session key start and end sequence numbers obtained by the key controller based on the opposite OTN device sent by the cryptographic service platform and the QKD node information corresponding to the opposite OTN device, and obtain the session key corresponding to the session key start and end sequence numbers from the key pool corresponding to the QKD link between the QKD node belonging to the receiving OTN device and the QKD node belonging to the opposite OTN device.

17. The OTN decryption communication method based on quantum key distribution according to claim 16, characterized in that: The receiving OTN device and the key controller connected thereto are both provided with a master key pool, the master key pool stores a master key, and the key distribution message is obtained by encrypting the master key in the master key pool corresponding to the key controller; after receiving the key distribution message sent by the key controller connected to the receiving OTN device, the method further includes: Decrypt the key distribution message using a randomly corresponding master key in a master key pool corresponding to the receiving OTN device to obtain the session key; The session key is stored in a session key pool, and the session key is associated with a corresponding encryption policy.

18. A session key distribution method, characterized in that: Applied to a key controller, the method comprises: Receive the key application message sent by the local OTN device; After verifying that the key application message is passed, query the cryptographic service platform for the QKD node information of the peer OTN device; Obtain the session key and key start and end sequence numbers from the key pool corresponding to the QKD link between the QKD node of the local OTN device and the QKD node of the opposite OTN device, and report the key start and end sequence numbers to the cryptographic service platform so that the cryptographic service platform sends the key start and end sequence numbers and the QKD node information of the local OTN device to the key controller corresponding to the opposite OTN device; Based on the session key and the key start and end sequence numbers, a key distribution message is generated and sent to the local OTN device.

19. The session key distribution method according to claim 18, characterized in that: A master key pool is set in both the local OTN device and the opposite OTN device, and a master key is stored in the master key pool; The key application message is encrypted by randomly selecting a master key from the corresponding master key pool of the local OTN device.

20. The session key distribution method according to claim 18, wherein: After verifying that the key application message is passed, querying the cryptographic service platform for the QKD node information of the peer OTN device includes: Selecting a corresponding master key from a master key pool corresponding to a key controller connected to the local OTN device to verify the key application message; After verification, query the cryptographic service platform for the QKD node information of the peer OTN device; The cryptographic service platform stores the mapping relationship between OTN devices and QKD nodes, as well as the connection topology of encryption ports between different OTN devices and the corresponding encryption strategies.

21. The session key distribution method according to claim 18, characterized in that: The generating a key distribution message based on the session key and the key start and end sequence numbers and sending the message to the local OTN device includes: Generate a key distribution message based on the session key and the key start and end sequence numbers; The key distribution message is encrypted using the master key in the corresponding master key pool and then sent to the local OTN device.

22. An OTN device, characterized in that: The OTN equipment includes: A key application module, used for applying for a session key from a quantum key distribution network and associating the session key with a corresponding encryption policy; The payload encryption and decryption module is used to divide the frame structure of any layer in the optical path layer into an overhead area and a payload area, and when the current sender OTN device supports adding information to the overhead area, add the session key sequence number used for encrypting the current frame of the current port to the overhead area, encrypt the payload area of ​​the current frame using the session key based on the encryption strategy, and then send the entire frame to the opposite end OTN device; and when the current sender OTN device does not support adding information to the overhead area, encrypt the payload area of ​​the current frame using the session key based on the encryption strategy, and then send it to the opposite end OTN device; The key synchronization control module is used to periodically send the key to the corresponding OTN device when the current sending OTN device does not support additional information in the overhead area. The OTN device at the end sends a session key synchronization message.

23. An OTN device, characterized in that: The OTN equipment includes: A key application module is used to receive a session key issued by a quantum key distribution network and associate the session key with a corresponding encryption strategy; The key synchronization control module is used to obtain the session key sequence number used for encrypting the incoming traffic of the current port from the key synchronization message sent by the opposite end OTN device when the current receiving end OTN device does not support additional information in the overhead area; The payload encryption and decryption module is used to obtain the session key serial number used for encrypting the current frame of the port inbound traffic from the overhead area or obtain the session key serial number used for encrypting the port inbound traffic from the key synchronization message sent by the opposite OTN device, and obtain the session key associated with the encryption policy based on the session key serial number to decrypt the ciphertext information sent by the opposite OTN device.

24. A key controller, characterized in that: The key controller comprises: A key application receiving module is used to receive a key application message sent by the local OTN device; The key application verification module is used to verify that the key application message is passed and query the cryptographic service platform for the QKD node information of the opposite OTN device; The session key acquisition module is used to obtain the session key and the key start and end sequence numbers from the key pool corresponding to the QKD link between the QKD node of the local OTN device and the QKD node of the opposite OTN device, and report the key start and end sequence numbers to the cryptographic service platform so that the cryptographic service platform sends the key start and end sequence numbers and the QKD node information of the local OTN device to the key controller corresponding to the opposite OTN device; The key distribution message generation module is used to generate a key distribution message based on the session key and the key start and end sequence numbers and send the message to the local OTN device.

25. An OTN encryption and decryption communication system based on quantum key distribution, characterized in that: The system includes: a first OTN device and a second OTN device, the first OTN device is connected to a first key controller via a first OTN controller, the second OTN device is connected to a second key controller via a second OTN controller, the first key controller and the second key controller are both connected to a cryptographic service platform, and the first key controller and the second key controller are both connected to a quantum key distribution network; The first key controller and the second key controller are used to obtain or transmit the session key to the OTN device in the domain according to the information of the opposite OTN device provided by the cryptographic service platform; The first OTN controller and the second OTN controller are used to establish a key distribution network channel between the OTN equipment in the domain and the corresponding key controller; The first OTN device is used to encrypt the payload using the OTN encryption communication method based on quantum key distribution according to any one of claims 1 to 10 to obtain ciphertext information; The second OTN device is used to decrypt the ciphertext information sent by the first OTN device by using the OTN decryption communication method based on quantum key distribution as described in any one of claims 11 to 17.

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